U.S. patent number 5,954,259 [Application Number 08/883,790] was granted by the patent office on 1999-09-21 for self-contained powered surgical apparatus for applying surgical fasteners.
This patent grant is currently assigned to United States Surgical Corporation. Invention is credited to Daniel E. Alesi, Richard N. Granger, Dominick L. Mastri, Kenneth E. Toso, Frank J. Viola, Wayne P. Young.
United States Patent |
5,954,259 |
Viola , et al. |
September 21, 1999 |
Self-contained powered surgical apparatus for applying surgical
fasteners
Abstract
A self-contained powered surgical apparatus for applying
surgical fasteners to body tissue is disclosed which includes a
handle assembly, a gear motor assembly disposed within the handle
assembly, a power source disposed within the handle assembly for
energizing the motor assembly, an elongated body extending distally
from the handle assembly, a cartridge assembly detachably connected
to a distal end portion of the elongated body, and an elongated
drive shaft extending through the elongated body and detachably
coupling the motor assembly to the cartridge assembly.
Inventors: |
Viola; Frank J. (Sandy Hook,
CT), Alesi; Daniel E. (Sherman, CT), Mastri; Dominick
L. (Bridgeport, CT), Young; Wayne P. (Brewster, CT),
Granger; Richard N. (Huntington, CT), Toso; Kenneth E.
(Wilton, CT) |
Assignee: |
United States Surgical
Corporation (Norwalk, CT)
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Family
ID: |
23102987 |
Appl.
No.: |
08/883,790 |
Filed: |
June 27, 1997 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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319852 |
Oct 7, 1994 |
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287455 |
Aug 5, 1994 |
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Current U.S.
Class: |
227/176.1;
227/178.1; 227/180.1; 227/79 |
Current CPC
Class: |
A61B
17/07207 (20130101); A61B 2017/00398 (20130101); A61B
2017/2933 (20130101); A61B 2017/0046 (20130101); A61B
2017/00473 (20130101); A61B 2017/2929 (20130101); A61B
2017/07214 (20130101); A61B 2017/2905 (20130101) |
Current International
Class: |
A61B
17/068 (20060101); A61B 17/072 (20060101); A61B
17/28 (20060101); A61B 17/00 (20060101); A61B
017/068 () |
Field of
Search: |
;227/176.1,175.1,178.1,180.1,19 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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0536903 |
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0539762 |
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0552050 |
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Jul 1993 |
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0593920 |
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Apr 1994 |
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0598579 |
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EP |
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0621006 |
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Oct 1994 |
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EP |
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2660851 |
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Oct 1991 |
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FR |
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2903159 |
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Jul 1980 |
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DE |
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3114135 |
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Oct 1982 |
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DE |
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4213426 |
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Oct 1992 |
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DE |
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51-149985 |
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May 1975 |
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JP |
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659146 |
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Apr 1979 |
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SU |
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9308754 |
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May 1993 |
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WO |
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9314706 |
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Aug 1993 |
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WO |
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Primary Examiner: Smith; Scott A.
Parent Case Text
CROSS REFERENCE TO RELATED APPLICATIONS
This is a continuation of application Ser. No. 08/319,852 filed on
Oct. 7, 1994 abandoned, which is a continuation-in-part of
application Ser. No. 08/287,455 filed Aug. 5, 1994 now abandoned,
the contents of which are incorporated herein by reference.
Claims
What is claimed is:
1. A self-contained powered surgical apparatus for applying
surgical fasteners to body tissue comprising:
a) a handle assembly;
b) a motor assembly disposed within the handle assembly;
c) a power source disposed within the handle assembly for
energizing the motor assembly;
d) an elongated body extending distally from the handle
assembly;
e) a cartridge assembly detachably connected to a distal end
portion of the elongated body and including:
i) a housing supporting a plurality of surgical fasteners;
ii) an anvil associated with the housing and mounted for movement
between an open position and a closed position;
iii) an actuation mechanism configured to translate relative to the
housing and the anvil to progressively move the anvil from the open
position to the closed position and to sequentially eject surgical
fasteners from the housing to be formed against the anvil;
iv) an axial drive screw threadably associated with the actuation
mechanism for effectuating the translation thereof; and
f) an elongated drive shaft extending through the elongated body
and detachably coupling the axial drive screw of the cartridge
assembly to the motor assembly.
2. A powered surgical apparatus as recited in claim 1, wherein the
handle assembly includes an elongate barrel portion within which
the motor assembly is disposed, and a depending handle gripping
portion within which the power source is disposed.
3. A powered surgical apparatus as recited in claim 1, further
comprising a trigger mechanism associated with the handle assembly
for selectively actuating the motor assembly.
4. A powered surgical apparatus as recited in claim 3, further
comprising a switching mechanism associated with the trigger
mechanism for selectively reversing the polarity of the motor
assembly.
5. A powered surgical apparatus as recited in claim 4, wherein the
elongated body and cartridge assembly are rotatable with respect to
the handle assembly.
6. A powered surgical apparatus as recited in claim 1, further
comprising means for preventing rotation of the elongated body and
the cartridge assembly.
7. A powered surgical apparatus as recited in claim 5, wherein the
preventing means comprises a plurality of indentations
circumferentially disposed about a distal portion of the handle
assembly, and an annular collar formed of a resilient material and
mounted about a proximal end portion of the elongated body, the
annular collar including a pair of diametrically opposed radially
inwardly extending protuberances dimensioned to normally engage the
indentations formed on the handle assembly, and which are
disengaged from the indentations by applying a radially inwardly
directed force on the collar.
8. A powered surgical apparatus as recited in claim 1, wherein the
cartridge assembly is detachably mounted to the elongated body by a
bayonet-type coupling arrangement.
9. A powered surgical apparatus as recited in claim 8, wherein the
bayonet-type coupling includes an engagement slot defined in a
distal end portion of the elongated body and a corresponding
engagement pin associated with a proximal end portion of the
cartridge assembly.
10. A powered surgical apparatus as recited in claim 1, wherein a
distal end of the elongated drive shaft is releasably coupled to a
proximal end of the axial drive screw by a spring biased coupling
mechanism.
11. A powered surgical apparatus as recited in claim 10, wherein
the coupling mechanism includes a compression spring, the spring
facilitating axial alignment of the proximal end of the axial drive
screw and the distal end of the elongated drive shaft.
12. A power surgical apparatus as recited in claim 10, further
comprising a shaft coupling interconnecting the elongated drive
shaft and the axial drive screw, the shaft coupling being rotatably
fixed but longitudinally slidable with respect to the drive shaft
and being longitudinally biased into operable engagement with the
axial drive screw, and a cartridge coupling operably connected to
the axial drive screw, the cartridge coupling having proximally
extending teeth and the shaft coupling having distally extending
teeth, the shaft coupling teeth being biased into engagement with
the cartridge coupling teeth.
13. A cartridge assembly for a surgical apparatus configured to
sequentially apply a plurality of surgical fasteners to body
tissue, the apparatus including an elongated body and an actuator
mounted for axial rotation within the elongated body, the cartridge
assembly comprising:
a) a housing supporting a plurality of surgical fasteners and
configured to be detachably mounted to a distal end portion of the
elongated body of the apparatus;
b) an anvil associated with the housing and mounted for movement
with respect thereto between an open position and a closed
position;
c) an actuation assembly configured to translate relative to the
housing and the anvil to progressively move the anvil from the open
position to the closed position and to concomitantly sequentially
eject surgical fasteners from the housing to be formed against the
anvil; and
d) an axial drive screw thredably associated with the actuation
assembly for effectuating the translation thereof, a proximal end
of the drive screw being configured to detachably couple with a
distal end of the actuator, whereby axial rotation of the actuator
causes longitudinal translation of the actuation assembly.
14. A cartridge assembly as recited in claim 13, further comprising
a cutting blade configured to translate through the cartridge
assembly in conjunction with the actuation assembly to form an
incision in stapled body tissue.
15. A cartridge assembly as recited in claim 14, wherein the anvil
is normally biased into the open position.
16. A cartridge assembly as recited in claim 15, wherein the anvil
includes a fastener forming surface against which fasteners are
driven when ejected from the housing, and an opposed outer camming
surface.
17. A cartridge assembly as recited in claim 16, wherein the
actuation assembly includes a cylindrical roller cam dimensioned
and configured to engage the outer camming surface of the anvil to
effect the progressive closure thereof during the longitudinal
translation of the actuation assembly.
18. A cartridge assembly as recited in claim 17, wherein a slot is
defined in the anvil to receive the cam roller and permit the anvil
to return to a normally biased open position at the conclusion of a
fastening operation.
19. A surgical apparatus comprising:
a) a handle assembly;
b) an elongated body extending distally from the handle assembly;
and
c) a cartridge assembly detachably connected to the elongated body
by a bayonet-type coupling, the cartridge assembly comprising:
i) a housing supporting a plurality of surgical fasteners;
ii) an anvil movable with respect to the housing between open and
closed positions;
iii) an actuation mechanism configured to translate relative to the
housing and anvil to move the anvil from the open to the closed
position and to eject the surgical fasteners from the housing to be
formed against the anvil; and
iv) a drive member operably associated with the handle assembly to
effect translation of the actuation mechanism.
20. A surgical apparatus as recited in claim 19, wherein the drive
member is an axial drive screw.
21. A surgical apparatus as recited in claim 20, further including
a motor disposed within the handle assembly and an elongated drive
shaft extending through the elongated body, the elongated drive
shaft coupling the axial drive screw of the cartridge assembly to
the motor assembly.
22. A surgical apparatus as recited in claim 21, further comprising
a trigger mechanism associated with the handle assembly for
selectively actuating the motor assembly.
23. A surgical apparatus as recited in claim 21, further comprising
a shaft coupling interconnecting the elongated drive shaft and the
axial drive screw, the shaft coupling being rotatably fixed but
longitudinally slidable with respect to the drive shaft and being
longitudinally biased into operable engagement with the axial drive
screw, and a cartridge coupling operably connected to the axial
drive screw, the cartridge coupling having proximally extending
teeth and the shaft coupling having distally extending teeth, the
shaft coupling teeth being biased into engagement with the
cartridge coupling teeth.
24. A surgical apparatus as recited in claim 21, wherein the handle
assembly includes an elongate barrel portion within which the motor
assembly is disposed, and a depending handle gripping portion
within which a power source is disposed.
25. A surgical apparatus as recited in claim 21, further comprising
a switching mechanism associated with a trigger mechanism for
selectively reversing the polarity of the motor assembly, and
wherein the cartridge is detachably mounted to the elongated body
by a bayonet-type coupling arrangement.
26. A surgical apparatus as recited in claim 19, further including
a motor assembly and a power source disposed within the handle
assembly.
Description
BACKGROUND
1. Technical Field
This application relates to a surgical apparatus, and more
particularly, to an apparatus for sequentially applying a plurality
of surgical fasteners to body tissue and optionally incising the
fastened tissue.
2. Background of Related Art
Surgical devices wherein tissue is first grasped or clamped between
opposing jaw structure and then joined by means of surgical
fasteners are well known in the art. In some instruments a knife is
provided to cut the tissue which has been joined by the fasteners.
The fasteners are typically in the form of surgical staples
however, two part polymeric fasteners are also utilized.
Instruments for this purpose can comprise two elongated members
which are respectively used to capture or clamp tissue. Typically,
one of the members carries a disposable cartridge which houses a
plurality of staples arranged in at least two lateral rows while
the other member comprises an anvil which defines a surface for
forming the staple legs as the fasteners are driven from the edge.
Generally, the stapling operation is effected by a pusher which
travels longitudinally through the cartridge carrying member, with
the pusher acting upon the staples to sequentially eject them from
the cartridge. A knife may travel with the pusher between the
staple rows to longitudinally cut and/or open the stapled tissue
between the rows of staples. Such instruments are disclosed in U.S.
Pat. No. 3,079,606 to Bobrov, et al and U.S. Pat. No. 3,490,675 to
Green.
A later stapler disclosed in U.S. Pat. No. 3,499,591 applies a
double row of staples on each side of the incision. This is
accomplished by providing a cartridge assembly in which a cam
member moves through an elongate guide path between two sets of
staggered staple carrying grooves. Staple drive members are located
within the grooves and are positioned in such a manner so as to be
contacted by the longitudinally moving cam to effect ejection of
the staples. Other examples of such staplers are disclosed in U.S.
Pat. Nos. 4,429,695 and 5,065,929.
Each of the instruments described above were designed for use in
conventional surgical procedures wherein surgeons have direct
manual access to the operative site. However, in endoscopic or
laparoscopic procedures, surgery is performed through a small
incision or through narrow a cannula inserted through small
entrance wounds in the skin. In order to address the specific needs
of endoscopic and/or laparoscopic surgical procedures, endoscopic
surgical stapling devices have been developed and are disclosed in
U.S. Pat. Nos. 5,040,715 and 5,318,221. In general, these
instruments are provided with clamping structure to effect
approximation of an anvil and a cartridge to secure tissue
therebetween, and staple firing structure to effect sequential
ejection of a plurality of fasteners from the cartridge after the
tissue has been secured.
The instruments discussed above all require some degree of manually
applied force in order to clamp, fasten and/or cut tissue. Surgeons
have thus recognized the benefits of using self-powered instruments
that are actuable with only a limited degree of physical force.
Self-powered surgical instruments have been provided to serve these
needs and include both gas powered surgical staplers, as shown, for
example, in U.S. Pat. No. 5,312,023, and electrically powered
surgical instruments as described in U.S. Pat. Nos. 4,365,638 and
5,258,007, and European Patent Application No. 0 552 050. In
general, prior art electrically powered surgical instruments have
been driven by external power sources. The instruments were
connected to the power sources by conductive cables. Such cables
could, however, become entangled during a surgical procedure,
thereby complicating the operation. It would therefore be
beneficial to provide a self-contained powered surgical apparatus
for applying surgical fasteners to body tissue. It would also be
beneficial if such self contained powered apparatus could be
reloadable.
SUMMARY
The subject application is directed to a self-contained powered
surgical apparatus for applying surgical fasteners to body tissue.
The apparatus includes a handle assembly, a motor assembly disposed
within the handle assembly, a power source disposed within the
handle assembly for energizing the motor assembly, an elongated
body extending distally from the handle assembly, and a cartridge
assembly detachably connected to a distal end portion of the
elongated body.
The cartridge assembly includes a housing supporting a plurality of
surgical fasteners, an anvil associated with the housing and
mounted for movement between an open position and a closed
position, an actuation mechanism configured to translate relative
to the housing and the anvil to progressively move the anvil from
the open position to the closed position and to sequentially eject
surgical fasteners from the housing to be formed against the anvil,
and an axial drive screw threadably associated with the actuator
for effectuating the longitudinal translation thereof. The powered
surgical apparatus further includes an elongated drive shaft which
extends through the elongated body and couples the motor assembly
to the axial drive screw of the cartridge assembly.
Preferably, the handle assembly includes an elongate barrel portion
within which the motor assembly is disposed, and a depending handle
gripping portion within which the power source is disposed. A
trigger mechanism is associated with the handle assembly for
selectively actuating the motor assembly, and a switching mechanism
is associated with the trigger mechanism for selectively reversing
the polarity of the motor assembly.
Preferably, the elongated body and the cartridge assembly can
rotate axially with respect to a longitudinal axis of the elongated
body. Means are preferably provided for preventing such rotation
comprising a plurality of recesses formed in and circumferentially
disposed about a distal portion of the handle assembly, and an
annular collar which is formed of a resilient material and mounted
about a proximal end portion of the elongated body. The annular
collar includes a pair of diametrically opposed radially inwardly
extending protuberances which are dimensioned and configured to
engage the circumferenfially disposed recesses. When the
protuberances are engaged in respective recesses, rotation of the
elongated body with respect to the handle assembly is prevented.
Application of a radially inwardly directed force disengages the
protuberences from the recesses to allow rotation.
Further features of the powered surgical apparatus of the subject
application will become more readily apparent to those skilled in
the art from the following detailed description of the apparatus
taken in conjunction with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
Various embodiments of the surgical apparatus of the subject
application will be described hereinbelow with reference to the
drawings wherein:
FIG. 1 is a perspective view of a powered surgical stapling
apparatus constructed in accordance with a preferred
embodiment;
FIG. 2 is a side elevational view in cross-section of the handle
assembly of the powered surgical stapling apparatus of FIG. 1;
FIG. 2a is a perspective view of the elongated body portion and the
handle assembly with one of the housing halves removed to
illustrate the motor assembly;
FIG. 2b is a schematic representation of the switching mechanism
for selectively controlling the operation of the surgical
apparatus;
FIG. 3 is a cross-sectional view taken along line 3--3 of FIG. 2
with the rotation collar engaged with the barrel portion of the
handle assembly;
FIG. 4 is a cross-sectional view taken along line 3--3 of FIG. 2
with the rotation collar disengaged from the handle assembly to
allow rotation of the elongated body portion;
FIG. 5 is an exploded perspective view of the cartridge assembly of
the powered surgical apparatus illustrated in FIG. 1;
FIG. 6 is a perspective view of a distal end portion of the drive
shaft of the powered surgical apparatus of FIG. 1 illustrating the
coupling arrangement for detachably connecting the cartridge
assembly of FIG. 5 to the drive shaft;
FIGS. 7 and 8 are side elevational views in partial cross-section
of a distal end portion of the instrument body illustrating the
connection of the carridge assembly of FIG. 5 to the elongated body
portion;
FIG. 9 is a side elevational view in cross-section illustrating the
cartridge assembly of the surgical apparatus of FIG. 1 prior to
firing the fasteners;
FIG. 10 is a side elevational view in cross-section illustrating
the cartridge assembly of the surgical apparatus of FIG. 1
subsequent to the fasteners being fired; and
FIG. 11 is a perspective view of the powered surgical stapling
apparatus of FIG. 1 inserted through a trocar cannula.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
In the drawings and in the description which follows, the term
"proximal", as is traditional, will refer to the end of the
apparatus which is closest to the operator, while the term "distal"
will refer to the end of the apparatus which is furthest from the
operator.
The present apparatus shall be discussed in terms of both
endoscopic procedures and apparatus. However, use herein of terms
such as "endoscopic", "endoscopically", and "endoscopic portion",
among others, should not be construed to limit the present
invention to an apparatus for use only in conjunction with an
endoscopic tube. To the contrary, it is believed that the present
invention may find use in procedures wherein access is limited to a
small incision including but not limited to arthroscopic and/or
laparoscopic procedures.
Referring now to the drawings wherein like reference numerals
identify similar structural elements of the subject invention,
there is illustrated in FIG. 1 a self-contained powered surgical
stapler constructed in accordance with a preferred embodiment of
the subject invention and designated generally by reference numeral
10. Surgical stapler 10 is configured to clamp body tissue, apply a
plurality of surgical fasteners to the body tissue, and form an
incision in the fastened body tissue during a laparoscopic surgical
procedure. In brief, surgical stapler 10 includes a handle portion
12, an elongate body portion 14 extending distally from handle
portion 12, and a cartridge assembly 16 detachably connected to a
distal end of body portion 14.
Referring to FIGS. 2 and 2a, the handle portion 12 of surgical
apparatus 10, composed of two housing halves, includes an elongated
barrel section 18 and a handle gripping section 20. A motor
assembly 22 having an output shaft (not shown) is disposed within
the barrel section 18 and includes a gear set 24 for reducing the
rotational speed of the output shaft and increasing the torque
delivered by the motor assembly. Gear set 24 includes a pinion gear
26 which is directly driven by the output shaft of motor assembly
22. Pinion gear 26 drives a first set of planetary gears 28 which
are supported on a carrier 30. The pinion portion of carrier 30
then drives the second set of planetary gears 34 which in turn
drives the hub member 36. The ring gear 32 remains stationary,
acting as a reaction point for planetary gears 28 and 34. A
reception port 38 is formed in hub member 36 for receiving the
proximal end 40 of an elongated drive shaft 42. Drive shaft 42
extends from hub 36 through the elongate body portion 14 of
surgical apparatus 10 to the cartridge assembly 16. A shaft
coupling is provided at the distal end of drive shaft 42 for
detachably connecting the cartridge assembly 16 to the drive shaft
42. This arrangement will be discussed in greater detail below with
respect to FIG. 6.
With continued reference to FIGS. 2 and 2a, motor assembly 22 is
energized by a pair of power cells 45a and 45b which are disposed
within the handle gripping section 20 of handle portion 12. As
shown, handle portion 12 extends substantially perpendicular to the
barrel portion 18. The power cells 45a, 45b can be lithium,
alkaline, or nickel cadmium type bathes. A trigger 44 projects from
gripping section 20 for controlling the operation of motor assembly
22. Preferably, trigger 44 is connected to a switching assembly 46
by a link bar 48. The switching assembly is preferably a
double-pole-double-throw (DPDT) switch and is electrically
connected to motor assembly 22. Preferably, the switch includes a
first position corresponding to the output shaft of the motor
assembly rotating in a first direction, a second position
corresponding to the output shaft rotating in a second direction,
and a third position wherein the motor assembly is not in
operation. DPDT switching assemblies of this type are well known to
the those skilled in the art.
FIG. 2b is a schematic representation of the switching mechanism.
As shown, terminal T3 is wired to terminal A of the motor and
terminal T4 is wired to terminal B of the motor. The positive
terminal of the power cell 45a is connected to positive terminal T5
and the negative terminal of the power cell 45b is connected to
negative terminal T6. When link bar 48 is moved proximally upon
squeezing trigger 44, the two middle terminals T3, T4 connect to
the respective rear terminals T5, T6. Thus, terminal A of the motor
will be connected to the positive terminal of the switch and
terminal B of the motor will be connected to the negative terminal
of the switch, thereby rotating the motor shaft in a first
direction to drive shaft 42 in a first direction to fire the
fasteners. If it is desired at any time to stop firing, the trigger
44 is released to disconnect terminals T3, T4 from T5, T6. If it is
desired to unclamp the tissue after the firing stroke has begun,
trigger 44 is pulled distally so that the middle terminals T3 and
T4 connect to front terminals T1, T2. Thus, terminal A of the motor
will be connected to the negative terminal of the switch and
terminal B will be connected to the positive terminal of the switch
thereby reversing the direction of the motor and drive shaft.
Referring to FIGS. 3 and 4 in conjunction with FIGS. 2 and 2a,
powered surgical apparatus 10 includes a rotator mechanism 50 for
enabling axial rotation of the body portion 14 relative to the
handle portion 12 to increase the operative range of the instrument
Rotator mechanism 50 includes an annular collar 52 formed of a
resilient material and connected to the proximal end of body
portion 14 by a threaded fastener 51. A pair of diametrically
opposed protuberances 56a and 56b extend radially inwardly from the
inner surface 52a of collar 52 for selectively engaging a plurality
of correspondingly configured recesses 58 defined about the
circumference of the distal end portion of barrel section 18. When
the protuberances 56a, 56b engage recesses 58 of barrel portion 58,
collar 52 is locked in position and body portion 14 cannot rotate.
Thus the body portion 14 will remain fixed as the drive shaft 42
extending therethrough rotates during a fastener applying
operation.
A pair of diametrically opposed disengagement pads 60a and 60b are
provided on an outer surface 52b of collar 52, 90.degree. out of
phase from the protuberances to release the protuberances to allow
rotation of collar 52. Thus to axially rotate body portion 14
relative to handle portion 12, a radially inwardly directed force
is applied to pads 60a and 60b, as illustrated in FIG. 4, causing
portions 53a, 53b of the resilient collar 52 to flex radially
outwardly. This flexure disengages protuberances 56a and 56b from
corresponding recesses 58a and 58b. This frees collar 52 for
rotation, thereby allowing body portion 14 to be rotated relative
to the handle portion 12 to orient cartridge assembly 16 to a
desired position.
Turning now to cartridge assembly 16, and referring to FIG. 5,
cartridge assembly 16 is configured as a separate unit which is
detachably connected to the distal end of elongated body portion
14. This enables the apparatus to be reloaded with a fresh
cartridge for additional application of rows of fasteners. The
detachability feature also enables the instrument to be
manufactured as a semi-reusable instrument, if desired, wherein the
handle portion 12 and elongate body portion 14 are resterilized and
the cartridge assembly discarded after use. It is also contemplated
that the entire apparatus could be disposable.
Cartridge assembly 16 includes two main structural portions, a
cartridge adaptor 70 and an elongated housing channel 80. They are
mounted to one another by a threaded fastener 75.
Adapter 70 includes a mounting portion 72 at its proximal end
dimensioned for reception within the distal end of elongated body
portion 14. An axial bore 74 extends through mounting portion 72
for rotatably supporting a cylindrical cartridge coupling 76.
Cartridge coupling 76 is configured to connect at its distal end to
the proximal end of an axial drive screw 78. Coupling 76 is
detachably connected at its proximal end to a shaft coupling 140
which is connected to the distal end of drive shaft 42. This
coupling which transmits rotational motion from the drive shaft 42
to the drive screw 78 will be discussed in greater detail
below.
Housing channel 80 includes opposed side walls 80a and 80b, and a
floor 80c. An aperture 82 is defined in floor 80c adjacent the
proximal end of channel 80 for receiving fastener 75. Opposed
apertures 83a and 83b are defined in the side walls 80a and 80b of
housing channel 80 for receiving a pair of outwardly extending
flanges 84a and 84b which are formed adjacent the proximal end of
anvil member 86 and about which anvil member 86 pivots between
closed and open positions to capture and release body tissue. A
pair of spring members 85a and 85b are disposed within apertures
83a and 83b for biasing anvil 86 into an open position. Opposed
engagement notches 88a and 88b are also defined in side walls 80a
and 80b, adjacent the distal end of housing channel 80, for
receiving a pair of detents on retaining cartridge 90, one of which
is shown and designated by reference numeral 89. The detents are
formed monolithically with the fastener retaining cartridge 90 and
secure the cartridge within a distal portion of the housing channel
80.
With continuing reference to FIG. 5, cartridge assembly 16 includes
an elongate actuation beam 100 for progressively moving anvil
member 86 from an open position to a closed position with respect
to retainer cartridge 90, and for concomitantly effecting the
sequential ejection of a plurality of surgical fasteners from
retainer cartridge 90. Actuation beam 100 is driven by the axial
drive screw 78 which, as noted above, is driven by drive shaft 42.
An actuation sled 120 is configured to translate through fastener
retainer cartridge 90 to effectuate the ejection of surgical
fasteners therefrom. Actuation sled 120 includes a base portion
122, a plurality of spaced apart upstanding cam plates 124, and a
central drive plate 125. Each cam plate 124 has an angled cam
surface for sequentially engaging a plurality of staple drivers
(not shown) which drive surgical fasteners from retainer cartridge
90 through body tissue and into engagement with anvil depressions
formed in anvil member 86. The leading edge 100a of actuation beam
100 engages drive plate 125 to drive actuation sled 120 through
retainer cartridge 90. A cutting blade 130 is mounted on actuation
beam 100 adjacent leading edge 100a and is configured to translate
through cartridge assembly 16, trailing behind sled 120, to form an
incision in stapled body tissue.
A stationary support mount 92 is disposed within cartridge assembly
16 to both guide the longitudinal translation of actuation beam
100, and support the distal end 78a of axial drive screw 78. The
proximal end 78b of drive screw 78 engages coupling 76 which, as
noted above, is connected to drive shaft 42 via coupling 140. A
follower nut 94 is thredably associated with drive screw 78 and is
mounted within a follower housing 95.
Follower housing 95 is mounted in such a manner so as to translate
in a longitudinal direction in response to axial rotation of drive
screw 78. Proximal elongate beam extensions 96 and 98 of actuation
beam 100 operatively connect actuation beam 100 to follower housing
95 so that the actuation beam 100 translates distally with the
follower housing.
A distal end of actuation beam 100 includes a retention flange 102
for supporting a generally cylindrical cam roller 104 and an
engagement slot 106 for retaining a substantially planar cam beam
108. Cam roller 104 engages and translates relative to an upper
clamming surface 110 of anvil member 86 to effect the progressive
closure thereof as follower housing 95 and actuation beam 100
translate through housing channel 80 to fire the fasteners. Cam
beam 108 engages and translates relative to the outer surface of
the floor 80c of housing channel 80 to balance the forces exerted
upon anvil member 86 by cam roller 104 during closure. A
longitudinal slot 112 is defined in the floor 80c of housing
channel 80 and a corresponding longitudinal slot 114 is defined in
anvil member 86 to accommodate the longitudinal translation of
actuation beam 100. A transverse slot 114a is defined at the distal
end of anvil slot 114 to receive cam roller 104 at the end of its
translation, and thereby permit anvil member 86 to return to an
open position under the bias of spring 85a and 85b following a
fastening operation. Thus, the body tissue is automatically
unclamped as soon as all the fasteners have been fired.
Referring now to FIGS. 6-9, as noted hereinabove, the cartridge
assembly 16 of surgical apparatus 10 is configured as a separate
unit which is detachably mounted to the distal end of body portion
14 via a bayonet coupling. In addition, as noted above, axial drive
screw 78 is detachably connected to drive shaft 42 through
cartridge coupling 76 and shaft coupling 140. As best seen in FIG.
6, shaft coupling 140 is slidably supported in a cavity 142 formed
in the distal end of drive shaft 42. A transverse slot 144 is
formed in the distal end of coupling 140 for engaging a
corresponding teeth 145 extending from the proximal end of
cartridge coupling 76 (see also FIG. 5). A pin 146, which is
supported in opposed shaft slots 148a and 148b and extends through
openings 141 in shaft coupling 140, maintains shaft coupling 140 in
cavity 142 and permits the longitudinal translation of shaft
coupling 140 against the bias of a coupling spring 150. The
function of coupling spring 150 is two-fold. Firstly, if slot 144
of coupling 140 and teeth 145 of coupling 76 are not aligned when
cartridge assembly 16 is inserted into the distal end of body
portion 14, coupling spring 150 will compensate for the
misalignment and facilitate engagement of the couplings upon
initial rotation of drive shaft 42. This occurs by initial
compression of the spring 150 as teeth 145 abut surface 143 of
coupling 140. When drive shaft 42 initially rotates and slot 144
becomes aligned with teeth 145, the spring 150 forces coupling 140
distally so slot 144 engages teeth 145. The second function of
coupling spring 150, as best seen in FIGS. 7 and 8, is to bias
cartridge adaptor 70 in a distal direction when the bayonet
coupling which maintains cartridge assembly 16 in body portion 14
is engaged. The bayonet coupling includes a generally J-shaped
engagement slot 156 formed in body portion 14 and corresponding
engagement pins 158a and 158b which extend radially outwardly from
cartridge adaptor 70 (see also FIG. 5). During attachment of the
cartridge assembly 16, the proximal end of cartridge adaptor 70 is
axially inserted into the distal end of body portion 14
(compressing spring 150) and is rotated approximately 20.degree. to
engage pins 158a and 158b in corresponding slots 156a and 156b (see
FIG. 1). At such a time, coupling spring 150 urges shaft coupling
140 and adaptor 70 distally to maintain pins 158a and 158b in an
engaged position within slots 156a and 156b.
Referring to FIGS. 9-11, in operation, the apparatus is inserted
through a trocar cannula 200 to access the surgical site. When body
tissue is captured between anvil member 86 and retainer cartridge
90, trigger 44 is depressed to actuate motor assembly 22, and
thereby cause gear set 24 to transfer rotational motion to drive
shaft 42, which, in turn, transfers rotational motion to axial
drive screw 78 through couplings 76 and 140. At such a time,
follower housing 95 translates in a longitudinal direction, driving
actuation beam 100 distally. As actuation beam 100 translates
distally, cam roller 104 progressively moves anvil member 86 from
the normally biased open position shown in FIG. 9, to the closed
clamped position illustrated in FIG. 10. Concomitantly, actuation
sled 120 is driven from the proximal position illustrated in FIG.
9, through retention cartridge 90, to the distal-most position
shown in FIG. 10, sequentially driving surgical fasteners through
body tissue 160. When cam roller 104 reaches the distal end of
longitudinal slot 114, it drops into transverse slot 114a,
permitting anvil 86 to return to an open position and release the
stapled body tissue 160. At the conclusion of the fastener applying
operation, cartridge assembly 16 is manipulated in such a manner so
as to disengage pins 158a and 158b from slots 156a and 156b, and
detach carridge adaptor 70 from body portion 14. Thereafter, a new
cartridge assembly containing a plurality of surgical fasteners and
a staple firing sled disposed in a proximal position may be mounted
to the apparatus in the same manner as described above for another
stapling procedure.
Although the subject apparatus has been described with respect to
preferred embodiments, it will be readily apparent to those having
ordinary skill in the art to which it appertains that changes and
modifications may be made thereto without departing from the spirit
or scope of the appended claims.
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